1. Field of the Invention
The present invention relates to methods of making creping adhesives and using such adhesives for creping tissue paper. The creping adhesives of the present invention include polyamine-epihalohydrin resin and poly(vinyl alcohol) mixtures, and are useful in the manufacture of soft, absorbent tissue paper webs.
2. Background of the Invention and Related Information
Creping adhesives are used in the process of producing tissue and towel paper products in order to improve the quality of the manufactured product and to improve the productivity of machines producing these grades of paper [J. R. Nelson, Chemical Processing Aids in Papermaking: A Practical Guide 161-165 (K. J. Hipolit ed., TAPPI Press, Atlanta, Ga. 1992)].
Polyamidoamine-epichlorohydrin resins have been used as creping adhesives in the following patents: U.S. Pat. No. 5,388,807 to Espy et al., U.S. Pat. No. 5,786,429 to Allen, U.S. Pat. No. 5,902,862 to Allen and Canadian Patent No. 979,579 to Giles et al.
Attempts have been made to use poly(vinyl alcohol) or PVOH as a component of creping adhesive formulations.
For example, U.S. Pat. No. 5,025,046 to Soerens discloses creping adhesives comprising water and suspended solids containing poly(vinyl alcohol), polyethylene oxide and lignin sulfonate. The adhesive compositions are used in making creped tissue products to adhere a paper web to a rotating cylinder from which it is then creped by a doctor blade.
Also, U.S. Pat. No. 5,179,150 to Furman, Jr. et al. discloses a creping adhesive comprising an amide polymer and PVOH. The polymer of Furman, Jr. et al. has amide and glyoxal substituents which are responsible for thermosetting properties. The creping adhesive disclosed is used in creping cellulosic webs. Combinations of PVOH with thermosetting, cationic polyamide resins have been used as creping adhesive compositions. Such combinations are disclosed in U.S. Pat. No. 4,501,640 to Soerens for a creping adhesive comprising (1) an aqueous mixture of PVOH; and (2) a water-soluble, thermosetting cationic polyamide resin which provide increased adhesion in the manufacture of creped wadding.
U.S. Pat. No. 4,528,316 to Soerens discloses an aqueous adhesive comprising water, PVOH and a water-soluble, cationic polyamide which is phase compatible with the PVOH. The polyamide of Soerens is the reaction product of a saturated aliphatic acid such as adipic acid, and a polyalkylene polyamine such as diethylene triarmine which is farther reacted with epichlorohydrin to yield the water-soluble, cationic polyamide. Furthermore, the adhesive of Soerens is used to adhere tissue to a creping cylinder in the manufacture of creped wadding.
U.S. Pat. No. 4,684,439 to Soerens also discloses a wettable creping adhesive comprising an aqueous admixture of PVOH and water-soluble, thermoplastic polyamide resin. The resin is the reaction product of a polyalkylene polyamine, a saturated aliphatic dibasic carboxylic acid, and a poly(oxyethylene)diamine.
U.S. Pat. No. 4,788,243 to Soerens discloses a creping adhesive comprising PVOH and a water-soluble, thermoplastic polyamide resin. The resin of Soerens is phase-compatible with PVOH and comprises the reaction product of polyalkylene polyamine, a saturated aliphatic dibasic carboxylic acid, and poly(oxyethylene)diamine. Additionally, U.S. Pat. No. 5,865,950 to Vinson et al. discloses a method for dry creping tissue paper comprising the application of creping adhesives comprising PVOH and a water-soluble, thermosetting, cationic polyamide resin in at least two steps.
Furthermore, U.S. Pat. No. 5,490,903 to Chen et al. discloses a creping adhesive composition comprising ethoxylated acetylenic diol. The creping adhesive composition of Chen et al. is said to be useful for creping through-dried tissue webs. Polyamine-epihalohydrin resins have been widely used in paper production [H. H. Espy, in xe2x80x9cWet Strength Resins and Their Applicationxe2x80x9d, L. L. Chan, Ed., pp. 21-22, TAPPI Press, Atlantic Ga. (1994)]. Polyamine-epihalohydrin resins differ from polyamidoamine-epichlorohydrin resins by the lack of amide linkages. This lack of amide linkages makes polyamine-epihalohydrin resins less susceptible to degradation by hydrolysis than polyamide-epihalohydrin resins. Another distinction is the degree of branching. The reaction of epichlorohydrin with a polyamine results in a highly branched structure having a variety of functional groups, such as secondary alcohol, secondary amine, tertiary amine, azetidinium chloride and aminochlorohydrin. The higher level of branching has a strong effect on the physical, mechanical and theological properties of the polyamine-epihalohydrin resins.
The polyamine-epihalohydrin resins are prepared in a one-step process in which a polyamine and an epihalohydrin are reacted in an aqueous medium until the desired molecular weight is achieved. The reaction is then diluted and/or stabilized at an acidic pH with an added acid.
In contrast, polyamidoamine-epihalohydrin resins are prepared in a two-step process, which involves the polycondensation of a dicarboxylic acid and a polyamine to form a polyamidoamine prepolymer. The polyamidoamine prepolymer contains amide linkages and secondary amine groups in the backbone. This prepolymer then reacts with epihalohydrin in an aqueous solution with heating to build molecular weight and provide reactive functionality to the polymer. Once the desired molecular weight or level of viscosity is achieved, the reaction is diluted and/or stabilized at an acidic pH with the addition of an acid.
Polyamine-epihalohydrin resins and their methods of preparation have been described in patents such as U.S. Pat. No. 3,248,353 to Coscia and U.S. Pat. No. 3,567,659 to Nagy. The former discloses the preparation of a cationic, water-soluble polyamine-epichlorohydrin resin polymer. The latter discloses the preparation of a methylamine-cpichlorohydrin polymer and use of such polymer as a flocculant for suspended solids in sewage and mine effluent water, as well as dry strength agents for paper.
Other patents which disclose polyamine-epihalohydrin resins include U.S. Pat. No. 3,949,014 to Maki et al. in which the polyamine-epichlorohydrin resin is obtained by reacting epichlorohydrin with a polyamine resin having at least 2 amino groups per molecule, and an amphoteric high molecular weight compound. In addition, U.S. Pat. No. 4,129,528 to Petrovich et al. discloses resinous reaction products wherein the hydrohalide salt of a polyamine is condensed with an epihalohydrin to provide improved wet and dry strength to cellulosic substrates.
Further, compositions and methods of using polyamine-epihalohydrin resins as creping adhesive are disclosed in U.S. Pat. No. 5,660,687 to Allen et al. in which a composition comprising polyamine-epihalohydrin resin creping adhesive and a creping release agent are applied together or separately in the creping process. U.S. Pat. No. 5,833,806 to Allen et al. also discloses a method for creping fibrous webs comprising the application of a polyamine-epihalohydrin creping adhesive.
Despite many attempts to produce different kinds of creping adhesives, there still remains a need in the art for creping adhesives which provide improved adhesion. The present invention provides for methods of using strong creping adhesives which may be used in the creping process.
The present invention relates to methods of making creping adhesives and using such adhesives for creping tissue paper. The creping adhesives of the present invention include polyamine-epihalohydrin resin and PVOH, and are useful in the manufacture of soft, absorbent paper webs.
The present invention is directed to, methods of production of creping adhesives comprising polyamine-epihalohydrin resin and polyvinyl alcohol (PVOH) and use for creping paper webs.
In particular, the present invention is advantageous in providing strong adhesion of the cellulosic fiber web to the dryer surface during the creping process to attain a soft, bulky tissue paper web.
The present invention provides a method of making and using a creping adhesive composition comprising polyamine-epihalohydrin and polyvinyl alcohol, wherein the polyamine-epihalohydrin resin is the reaction product of an epihalohydrin and a polyamine, the polyamine has the following formula:
H2Nxe2x80x94Axe2x80x94H,
wherein A is [CHZxe2x80x94(CH2)nxe2x80x94NRxe2x80x94]x, or [CH2xe2x80x94(CHZ)mxe2x80x94(CH2)nxe2x80x94NRxe2x80x94]x,
when A is [CHZxe2x80x94(CH2)nxe2x80x94NRxe2x80x94]x, n=1 to 7; x=1 to 6; Rxe2x95x90H or CH2Y; Zxe2x95x90H or CH3; and Yxe2x95x90CH2Z, H, NH2, or CH3,
when A is H2Nxe2x80x94[CH2xe2x80x94CHZ)mxe2x80x94(CH2)nxe2x80x94NRxe2x80x94]xxe2x80x94H, m=1 to 6; n=1 to 6; m+n=2 to 7; Rxe2x95x90H or CH2Y, Zxe2x95x90H or CH3; and Yxe2x95x90CH2Z, H, NH2, or CH3. The polyamine-epihalohydrin resin is formed at a temperature less than or equal to 60xc2x0 C., preferably at a temperature from about 25xc2x0 C. to about 60xc2x0 C., and most preferably at a temperature from about 30xc2x0 C. to about 45xc2x0 C.
Furthermore, the creping adhesive compositions used in the present invention may be present in the form of the reaction product of polyamine-epihalohydrin resin and polyvinyl alcohol.
The ratio by weight of polyamine-epihalohydrin resin:polyvinyl alcohol in the creping adhesive composition used in the present invention is in a range from about 99:1 to 1:99, preferably from about 95:5 to 5:95, and more preferably from about 90:10 to 10:90.
Further, the polyamine-epihalohydrin resin present in the creped paper web is from about 0.0001% to about 5%, preferably from about 0.0005% to about 1%, and most preferably from about 0.001% to about 0.5% by weight based on paper.
The polyvinyl alcohol present in the creped paper web is from about 0.0001% to about 5%, preferably 0.0005% to about 1%, and most preferably 0.001% to about 0.5% by weight based on paper.
Further, the molecular weight of the polyamine-epihalohydrin resin added to the creping adhesive used in the present invention is in a range from about 500 to about 1,000,000, preferably from about 2,500 to about 500,000, and most preferably from about 5,000 to about 250,000 Daltons before addition to form the adhesive.
The molecular weight of the polyvinyl alcohol added to the creping adhesive used in the present invention is in a range from about 10,000 to about 1,000,000, preferably from about 20,000 to about 500,000, and most preferably from about 50,000 to about 250,000 Daltons before addition to form the adhesive.
The degree of hydrolysis of the polyvinyl alcohol in the creping adhesive used in the present invention is from about 80% to about 90%, preferably from about 85% to about 99%, and most preferably from about 87% to about 98%.
Still further, the concentration of solids in the aqueous solution of the present invention is from about 0.01% to about 10% by weight of total polymer solids, preferably from about 0.2% to about 5%, and most preferably from about 0.1% to about 2.5% by weight of total polymer solids.
The fraction of polyamine-epihalohydrin resin present in the solids is from about 5% to about 95%, preferably from about 7.5% to about 92.5%, and most preferably from about 10% to about 90% by weight.
The fraction of polyvinyl alcohol present in the solids is from about 95% to about 5%, preferably from about 92.5% to about 7.5%, and most preferably from about 90% to about 10% by weight.
Still even further, the polyamines of the present invention include polyalkylene, polyaralkylene, polyalkarylene, or polyarylene amines. The polyaralkylene amines comprises 1-phenyl-2,4-pentane diamine, or 2-phenyl-1,3-propanediamnine. The polyarylene amines comprises phenylene diamine. The polyalkylene amines comprises ethylenediamine (EDA), bishexamethylenediamine (BHMT), hexamethylenediamine (HMDA), diethylenetriamine (DETA), triethyleneteramine (TETA), tetraethylenepentamine (TEPA), dipropylenetriamine (DNTA), tripropyleneteramine (TPTA), tetrapropylenepentamine (TPPA), N-methyl-bis-(aminopropyl)amine (MBAPA), spermine or spermidine.
Even further, the present invention comprises epihalohydrin such as epichlorohydrin, epibromohydrin or epiiodohydrin.
In addition, the creping composition used in the present invention may be in a form comprising at least one of aqueous, solid, dispersion, and aerosol.
Also, the method of the present invention comprises the simultaneous or individual application of a polyamine-epihalohydrin resin and a polyvinyl alcohol to a drying surface or paper web.
The present invention provides a method of creping cellulosic fiber webs which comprises the step of applying a creping adhesive to a drying surface, the creping adhesive comprising polyamine-epihalohydrin resin and polyvinyl alcohol.
According to the invention, the cellulosic fiber web may be adhered to the drying surface of a Yankee Dryer. The dry cellulosic fiber web is then creped from the drying surface with a creping instrument such as a doctor blade.
Furthermore, the present invention provides a method for creping cellulosic fiber webs which comprises applying a creping adhesive comprising the reaction product of the polyamine-epihalohydrin resin and polyvinyl alcohol.
In another aspect, the present invention provides a method of preparing a creping adhesive composition which comprises the step of combining a polyamine-epihalohydrin resin and a polyvinyl alcohol.
Furthermore, the present invention provides a method of preparing a creping adhesive composition comprising the reaction product of the polyamine-epihalohydrin resin and polyvinyl alcohol.
In still another aspect, the present invention provides a cellulosic fiber product which comprises polyamine-epihalohydrin resin and polyvinyl alcohol, and/or the reaction product thereof
The cellulosic fiber product may comprise other additives including chemical functional agents such as wet strength or dry strength binders, retention aids, surfactants, sizing agents, chemical softeners, fillers, flocculants and other crepe-facilitating components.